Methods and assemblies for forming features in composite components

ABSTRACT

Various methods and assemblies are provided for producing composite components having formed in features. For example, a method may comprise depositing a composite material on a base tool; aligning an aperture forming tool with a tooling aperture in the base tool; inserting the aperture forming tool through the composite material to form an aperture in the composite material; deploying a feature forming tool to press the composite material into one or more recesses; and processing the composite material with the feature forming tool in contact with the composite material. In some embodiments, the feature forming tool includes a stem extending through the composite material and into the base tool, as well as a feature forming head that is brought into contact with and processed with the composite material. In other embodiments, a tooling assembly holds a pin in place during processing to fix the pin in the composite component.

FIELD

The present subject matter relates generally to components made fromcomposite materials. More particularly, the present subject matterrelates to methods and assemblies for forming features in compositecomponents, such as composite components for gas turbine engines.

BACKGROUND

More commonly, non-traditional high temperature composite materials,such as ceramic matrix composite (CMC) and polymer matrix composite(PMC) materials, are being used in applications such as gas turbineengines. Components fabricated from such materials have a highertemperature capability compared with typical components, e.g., metalcomponents, which may allow improved component performance and/orincreased engine temperatures. However, forming accurate and precisefeatures, such as embossments, countersinks, counterbores, and the like,in composite components without weakening the composite material can bedifficult. For example, such features typically are machined in thecomposite component after processing, which often requires additionalcomposite material to provide an adequate machining area and cutsthrough layers of the composite material.

Improved methods and assemblies for forming features in compositecomponents would be useful. In particular, methods and assembliesallowed formed in features of composite components, rather than machinedin features, would be desirable. Formed in features of compositecomponents may result in stronger composite components, as well asreduce the amount of composite material required to form a component,which may reduce labor and material costs.

BRIEF DESCRIPTION

Aspects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

In one exemplary embodiment of the present subject matter, a method forforming features in a composite component is provided. The methodcomprises depositing a composite material on a base tool; aligning anaperture forming tool with a tooling aperture in the base tool;inserting the aperture forming tool through the composite material toform an aperture in the composite material; deploying a feature formingtool to press the composite material into one or more recesses; andprocessing the composite material with the feature forming tool incontact with the composite material. The processed composite materialforms a green state composite component. The feature forming toolcomprises a feature forming head that is configured to form a feature ofthe composite component.

In another exemplary embodiment of the present subject matter, a methodfor forming features in a composite component is provided. The methodcomprises depositing a composite material on a base tool; forming anaperture through the composite material; bringing a feature forming headof a feature forming tool into contact with the composite material; andprocessing the composite material with the feature forming head incontact with the composite material. The processed composite materialforms a green state composite component. The feature forming toolcomprises a stem extending through the composite material and into thebase tool, and the feature forming head is configured to form a featureof the composite component.

In a further exemplary embodiment of the present subject matter, amethod for forming features in a composite component is provided. Themethod comprises depositing a composite material on a tooling assembly;forming an aperture through the composite material; inserting a pin intothe aperture such that the pin extends through the composite materialand into the tooling assembly; and processing the composite materialwith the pin extending through the composite material. The processedcomposite material forms a green state composite component. The pin isfixed in the green state composite component such that the green statecomposite component includes the pin.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 provides a schematic cross-section view of an exemplary gasturbine engine according to various embodiments of the present subjectmatter.

FIG. 2 provides a schematic cross-section view of a composite componenthaving a formed in countersink feature and a formed in counterborefeature.

FIG. 3 provides an exploded perspective view of a composite materialdeposited on a base tool and a feature forming tool for forming one ormore features in the composite material, according to an exemplaryembodiment of the present subject matter.

FIG. 3A provides a cross-section view of the composite material, basetool, and feature forming tool, taken along the line 3A-3A of FIG. 3.

FIG. 3B provides a cross-section view of the composite material, basetool, and feature forming tool, taken along the line 3B-3B of FIG. 3.

FIGS. 4A, 4B, 4C, and 4D provide cross-section views of a portion of thefeature forming tool of FIG. 3, according to various exemplaryembodiments of the present subject matter.

FIGS. 5A and 5B provide cross-section views of a base tool and anaperture forming tool for forming an aperture in a composite materialdeposited on the base tool, according to an exemplary embodiment of thepresent subject matter.

FIG. 6 provides a cross-section view of a base tool, an aperture formingtool, and a guide tool for forming an aperture in a composite materialdeposited on the base tool, according to an exemplary embodiment of thepresent subject matter.

FIG. 7 provides a flow diagram of a method for forming one or morefeatures in a composite component according to an exemplary embodimentof the present subject matter.

FIGS. 8A and 8B provide cross-section views of a base tool and a featureforming tool for forming one or more features in a composite materialdeposited on the base tool, according to an exemplary embodiment of thepresent subject matter.

FIG. 9 provides a flow diagram of a method for forming one or morefeatures in a composite component according to an exemplary embodimentof the present subject matter.

FIGS. 10A, 10B, and 10C provide cross-section views of a base tool and afeature forming tool for forming one or more features in a compositematerial deposited on the base tool, according to exemplary embodimentsof the present subject matter.

FIGS. 11A through 11F provide a cross-section view of a base tool, anaperture forming tool, and a feature forming tool for forming anaperture and one or more features in a composite material deposited onthe base tool, according to an exemplary embodiment of the presentsubject matter.

FIG. 12 provides a flow diagram of a method for forming one or morefeatures in a composite component according to an exemplary embodimentof the present subject matter.

FIG. 13 provides a cross-section view of a base tool, a toolingassembly, a pin, and a feature forming tool for forming one or morefeatures in a composite material deposited on the base tool, accordingto an exemplary embodiment of the present subject matter.

FIG. 14 provides a cross-section view of a base tool, a toolingassembly, and a feature forming tool for forming one or more features ina composite material deposited on the base tool, according to anexemplary embodiment of the present subject matter.

FIG. 15 provides a flow diagram of a method for forming one or morefeatures in a composite component according to an exemplary embodimentof the present subject matter.

FIGS. 16A and 16B provide cross-section views of a tooling assembly anda feature forming tool for forming one or more features in a compositematerial deposited on the base tool, according to exemplary embodimentsof the present subject matter.

FIG. 17 provides a flow diagram of a method for forming one or morefeatures in a composite component according to an exemplary embodimentof the present subject matter.

FIGS. 18 and 19 provide cross-section views of a base tool and a featureforming tool for forming one or more features in a composite materialdeposited on the base tool, according to exemplary embodiments of thepresent subject matter.

DETAILED DESCRIPTION

Reference will now be made in detail to present embodiments of theinvention, one or more examples of which are illustrated in theaccompanying drawings. The detailed description uses numerical andletter designations to refer to features in the drawings. Like orsimilar designations in the drawings and description have been used torefer to like or similar parts of the invention. As used herein, theterms “first,” “second,” and “third” may be used interchangeably todistinguish one component from another and are not intended to signifylocation or importance of the individual components. The terms“upstream” and “downstream” refer to the relative direction with respectto fluid flow in a fluid pathway. For example, “upstream” refers to thedirection from which the fluid flows and “downstream” refers to thedirection to which the fluid flows.

Referring now to the drawings, wherein identical numerals indicate thesame elements throughout the figures, FIG. 1 is a schematiccross-sectional view of a gas turbine engine in accordance with anexemplary embodiment of the present disclosure. More particularly, forthe embodiment of FIG. 1, the gas turbine engine is a high-bypassturbofan jet engine 10, referred to herein as “turbofan engine 10.” Asshown in FIG. 1, the turbofan engine 10 defines an axial direction A(extending parallel to a longitudinal centerline 12 provided forreference) and a radial direction R. In general, the turbofan 10includes a fan section 14 and a core turbine engine 16 disposeddownstream from the fan section 14.

The exemplary core turbine engine 16 depicted generally includes asubstantially tubular outer casing 18 that defines an annular inlet 20.The outer casing 18 encases, in serial flow relationship, a compressorsection including a booster or low pressure (LP) compressor 22 and ahigh pressure (HP) compressor 24; a combustion section 26; a turbinesection including a high pressure (HP) turbine 28 and a low pressure(LP) turbine 30; and a jet exhaust nozzle section 32. A high pressure(HP) shaft or spool 34 drivingly connects the HP turbine 28 to the HPcompressor 24. A low pressure (LP) shaft or spool 36 drivingly connectsthe LP turbine 30 to the LP compressor 22.

For the depicted embodiment, fan section 14 includes a fan 38 having aplurality of fan blades 40 coupled to a disk 42 in a spaced apartmanner. As depicted, fan blades 40 extend outward from disk 42 generallyalong the radial direction R. The fan blades 40 and disk 42 are togetherrotatable about the longitudinal axis 12 by LP shaft 36. In someembodiments, a power gear box having a plurality of gears may beincluded for stepping down the rotational speed of the LP shaft 36 to amore efficient rotational fan speed.

Referring still to the exemplary embodiment of FIG. 1, disk 42 iscovered by rotatable front nacelle 48 aerodynamically contoured topromote an airflow through the plurality of fan blades 40. Additionally,the exemplary fan section 14 includes an annular fan casing or outernacelle 50 that circumferentially surrounds the fan 38 and/or at least aportion of the core turbine engine 16. It should be appreciated thatnacelle 50 may be configured to be supported relative to the coreturbine engine 16 by a plurality of circumferentially-spaced outletguide vanes 52. Moreover, a downstream section 54 of the nacelle 50 mayextend over an outer portion of the core turbine engine 16 so as todefine a bypass airflow passage 56 therebetween.

During operation of the turbofan engine 10, a volume of air 58 entersturbofan 10 through an associated inlet 60 of the nacelle 50 and/or fansection 14. As the volume of air 58 passes across fan blades 40, a firstportion of the air 58 as indicated by arrows 62 is directed or routedinto the bypass airflow passage 56 and a second portion of the air 58 asindicated by arrows 64 is directed or routed into the LP compressor 22.The ratio between the first portion of air 62 and the second portion ofair 64 is commonly known as a bypass ratio. The pressure of the secondportion of air 64 is then increased as it is routed through the highpressure (HP) compressor 24 and into the combustion section 26, where itis mixed with fuel and burned to provide combustion gases 66.

The combustion gases 66 are routed through the HP turbine 28 where aportion of thermal and/or kinetic energy from the combustion gases 66 isextracted via sequential stages of HP turbine stator vanes 68 that arecoupled to the outer casing 18 and HP turbine rotor blades 70 that arecoupled to the HP shaft or spool 34, thus causing the HP shaft or spool34 to rotate, thereby supporting operation of the HP compressor 24. Thecombustion gases 66 are then routed through the LP turbine 30 where asecond portion of thermal and kinetic energy is extracted from thecombustion gases 66 via sequential stages of LP turbine stator vanes 72that are coupled to the outer casing 18 and LP turbine rotor blades 74that are coupled to the LP shaft or spool 36, thus causing the LP shaftor spool 36 to rotate, thereby supporting operation of the LP compressor22 and/or rotation of the fan 38.

The combustion gases 66 are subsequently routed through the jet exhaustnozzle section 32 of the core turbine engine 16 to provide propulsivethrust. Simultaneously, the pressure of the first portion of air 62 issubstantially increased as the first portion of air 62 is routed throughthe bypass airflow passage 56 before it is exhausted from a fan nozzleexhaust section 76 of the turbofan 10, also providing propulsive thrust.The HP turbine 28, the LP turbine 30, and the jet exhaust nozzle section32 at least partially define a hot gas path 78 for routing thecombustion gases 66 through the core turbine engine 16.

It will be appreciated that turbofan engine 10 is provided by way ofexample only, and the present subject matter also may be applied toother engine configurations. Further, the present subject matterdescribed in greater detail below also may be applicable to othersystems, machines, mechanisms, structures, or the like. The use ofturbofan engine 10 provides a frame of reference, and the presentsubject matter need not be limited in applicability to only turbofanengines or similar structures.

In some embodiments, components of turbofan engine 10, particularlycomponents within or defining the hot gas path 78, may comprise acomposite material, such as a ceramic matrix composite (CMC) material, apolymer matrix composite (PMC) material, or other suitable compositematerial having high temperature capability. Composite materialsgenerally comprise a fibrous reinforcement material embedded in matrixmaterial, such as polymer or ceramic material. The reinforcementmaterial serves as a load-bearing constituent of the composite material,while the matrix of a composite material serves to bind the fiberstogether and act as the medium by which an externally applied stress istransmitted and distributed to the fibers.

Exemplary CMC materials may include silicon carbide (SiC), silicon,silica, or alumina matrix materials and combinations thereof. Ceramicfibers may be embedded within the matrix, such as oxidation stablereinforcing fibers including monofilaments like sapphire and siliconcarbide (e.g., Textron's SCS-6), as well as rovings and yarn includingsilicon carbide (e.g., Nippon Carbon's NICALON®, Ube Industries'TYRANNO®, and Dow Corning's SYLRAMIC®), alumina silicates (e.g.,Nextel's 440 and 480), and chopped whiskers and fibers (e.g., Nextel's440 and SAFFIL®), and optionally ceramic particles (e.g., oxides of Si,Al, Zr, Y, and combinations thereof) and inorganic fillers (e.g.,pyrophyllite, wollastonite, mica, talc, kyanite, and montmorillonite).For example, in certain embodiments, bundles of the fibers, which mayinclude a ceramic refractory material coating, are formed as areinforced tape, such as a unidirectional reinforced tape. A pluralityof the tapes may be laid up together (e.g., as plies) to form a preformcomponent. The bundles of fibers may be impregnated with a slurrycomposition prior to forming the preform or after formation of thepreform. The preform may then undergo thermal processing, such as a cureor burn-out to yield a high char residue in the preform, and subsequentchemical processing, such as melt-infiltration with silicon, to arriveat a component formed of a CMC material having a desired chemicalcomposition. In other embodiments, the CMC material may be formed as,e.g., a carbon fiber cloth rather than as a tape.

Similarly, PMC materials are typically fabricated by impregnating afabric or unidirectional tape with a resin (prepreg), followed bycuring. Prior to impregnation, the fabric may be referred to as a “dry”fabric and typically comprises a stack of two or more fiber layers(plies). The fiber layers may be formed of a variety of materials,nonlimiting examples of which include carbon (e.g., graphite), glass(e.g., fiberglass), polymer (e.g., Kevlar®) fibers, and metal fibers.Fibrous reinforcement materials can be used in the form of relativelyshort chopped fibers, generally less than two inches in length, and morepreferably less than one inch, or long continuous fibers, the latter ofwhich are often used to produce a woven fabric or unidirectional tape.PMC materials can be produced by dispersing dry fibers into a mold, andthen flowing matrix material around the reinforcement fibers, or byusing prepreg. For example, multiple layers of prepreg may be stacked tothe proper thickness and orientation for the part, and then the resinmay be cured and solidified to render a fiber reinforced composite part.Resins for PMC matrix materials can be generally classified asthermosets or thermoplastics. Thermoplastic resins are generallycategorized as polymers that can be repeatedly softened and flowed whenheated and hardened when sufficiently cooled due to physical rather thanchemical changes. Notable example classes of thermosplastic resinsinclude nylons, thermoplastic polyesters, polyaryletherketones, andpolycarbonate resins. Specific examples of high performancethermoplastic resins that have been contemplated for use in aerospaceapplications include polyetheretherketone (PEEK), polyetherketoneketone(PEKK), polyetherimide (PEI), and polyphenylene sulfide (PPS). Incontrast, once fully cured into a hard rigid solid, thermoset resins donot undergo significant softening when heated but, instead, thermallydecompose when sufficiently heated. Notable examples of thermoset resinsinclude epoxy, bismaleimide (BMI), and polyimide resins.

As stated, it may be desirable to form components within or defining thehot gas path 78, such as the jet exhaust nozzle section 32, fromcomposite materials such as CMC or PMC materials. Often, the componentsformed from composite materials require features of a certain shape orstyle, e.g., attachment features such as countersunk holes to allow thecomposite component to be attached to another component. For instance,the jet exhaust nozzle section 32 may comprise an exhaust case, as wellas a composite exhaust liner that preferably is attached to the exhaustcase. Thus, one or more features must be defined in the compositeexhaust liner for attaching the liner to the case. Rather than machiningsuch features into the composite exhaust liner after the liner isfabricated, using the subject matter described herein, these featurescan be formed in the liner during the fabrication process.

Referring now to FIGS. 2 through 7, assemblies and methods for formingfeatures in composite components will be described in greater detail. Aspreviously mentioned, composite components generally may be formed bylaying up plies of a composite material, such as CMC plies or PMC plies,in a desired shape and curing the plies to form a composite component.Typically, the composite plies are laid up on a tool or mold to helpdefine the desired shape. As depicted in FIG. 3, in an exemplaryembodiment of the present subject matter, a base tool 100, on which aplurality of composite plies 102 may be laid up, comprises one or morerecesses 104 that help define one or more features of a compositecomponent 90. As shown in FIG. 3A, a first recess 104 a may beconfigured for defining a countersink feature 106 in the compositecomponent 90 (FIG. 2) while a second recess 104 b, illustrated in FIG.3B, may be configured for defining a counterbore feature 108 in thecomposite component 90 (FIG. 2). Other recesses 104 also may be used todefine additional and/or different features in the composite component90. For example, the features may be oblong or polygonal and/or skewedor tilted with respect to one or more centerlines or axes of thecomposite component. Further, the features may be one or more featuresfor locating the composite component within an assembly, e.g., one ormore locating features for locating an exhaust liner within an exhaustassembly.

FIGS. 3, 3A, and 3B further illustrate that the composite plies 102 arelaid up on a proximal surface 100 a of the base tool 100; the base tool100 also comprises a distal surface 100 b opposite the proximal surface100 a. Once the plurality of composite plies 102 is laid up on the basetool 100, a feature forming tool 110 may be brought into contact withthe plurality of composite plies 102 that are supported on the base tool100. The feature forming tool 110 comprises a sheet 112 having one ormore inserts or raised portions 114 for forming one or more features ofthe composite component, such as the countersink feature 106 and thecounterbore feature 108 depicted in FIG. 2. For example, in theillustrated exemplary embodiment, a first insert 114 a (FIG. 3A) isconfigured to define the countersink feature 106, and a second insert114 b (FIG. 3B) is configured to define the counterbore feature 108. Thesheet 112 may be formed from a first material 116, and the one or moreinserts may be formed from a second material 118 that is harder than thefirst material. In exemplary embodiments, the first material 116 issilicone, such that the sheet 112 is formed from silicone and theinserts 114 are formed from a material 118 that is harder than silicone,e.g., a metal, polymer, or elastomer having a greater Shore hardnessthan silicone. Further, as illustrated in FIG. 3B, the base tool 100 mayinclude one or more alignment features 101 that help align the sheet 112and inserts 114 with the base tool 100 and recesses 104.

As shown in FIGS. 4A, 4B, 4C, and 4D, a variety of inserts 114 or insertconfigurations may be used in the feature forming tool 110. Referring toFIG. 4A, in some exemplary embodiments, an insert 114 may be formed fromthe same material as the sheet 112. That is, the sheet 112 and the oneor more inserts 114 may be formed from the first material 116, which maybe silicone in exemplary embodiments. In such embodiments, the inserts114 may be referred to as raised portions 114, wherein the portions 114protrude or extend from a surface 122 of the sheet 112. Turning to FIG.4B, in other exemplary embodiments, an insert 114 is formed from thesecond material 118 while the sheet 112 is formed from the firstmaterial 116. In the embodiment illustrated in FIG. 4B, the insert 114has a side 120 that extends away from and is non-planar with respect tothe surface 122 of the sheet 112, i.e., the side 120 is not parallel toor within the plane of the sheet surface 122. The first material 116 ofthe sheet 112 extends partially along the side 120 of the insert 114. Inother embodiments, such as depicted in FIG. 4C, the first material 116of the sheet 112 extends fully or completely along the side 120 of theinsert 114, i.e., to a surface 124 of the insert 114 that is parallelwith respect to the sheet surface 122. It will be appreciated thatgenerally frustoconical-shaped inserts 114 may have one non-planar side120 that extends away from the sheet surface 122, but inserts 114 havingother shapes may have more than one non-planar side 120 that extendsaway from the sheet surface 122, and the first material 116 may extendpartially or fully along at least one of the sides 120. Turning to FIG.4D, in yet other embodiments, an insert 114 is a thin disk of the secondmaterial 118, and the first material 116 extends fully along a perimeterP of the thin disk insert 114 to the insert surface 124 that generallyis parallel to the sheet surface 122. As shown in FIG. 4D, the perimeterP of the insert 114 extends away from and is non-planar with respect tothe surface 122 of the sheet 112. Of course, the inserts 114 illustratedin FIGS. 4A, 4B, 4C, and 4D are by way of example only, and featureforming tool 110 also may comprise inserts 114 having other shapesand/or configurations.

FIGS. 4A, 4B, 4C, and 4D further illustrate that the feature formingtool 110 comprises a transition area 126 between the sheet 112 and theinsert 114 protruding from the sheet 112. More particularly, in eachembodiment, the feature forming tool 110 gradually and smoothlytransitions from the planar sheet surface 122 to the insert 114, whichextends away from the surface 122. Further, where the first material 116of the sheet 112 extends partially along the insert side 120 as shown inFIG. 4B, the first material 116 extending along the side 120 isrelatively thin in depth, e.g., to avoid a step in the transition area126 as the feature forming tool 110 transitions from the first material116 of the sheet 112 to the second material 118 of the insert 114 alongthe insert side 120. That is, the relatively thin layer of the firstmaterial 116 that extends along the side 120 generally smoothlytransitions to the second material 118 of the insert 114, therebyavoiding a step in the surface defined by the first material 116 and thesecond material 118 that is parallel to the side 120.

Turning now to FIGS. 5A and 5B, the features of the composite componentalso may comprise one or more apertures 128, e.g., an aperture 128 maybe formed generally in the center of a countersink feature 106 and/or acounterbore feature 108 (FIG. 2), i.e., such that a centerline CL_(A) ofthe aperture 128 is the same as a centerline CL_(F) of the feature 106,108, or an aperture 128 may be formed in or as another feature of thecomposite component 90. Referring to FIG. 5A, in one embodiment, thebase tool 100 comprises a tooling aperture 130 extending from the distalsurface 100 b of the base tool 100 to one of the recesses 104, e.g.,first recess 104 a. More particularly, the tooling aperture 130 extendsfrom a distal end 130 b at the base tool distal surface 100 b to aproximal end 130 a at the recess 104 a. The tooling aperture 130 has acenterline CL_(T), which is co-extensive with or the same as the featurecenterline CL_(F). As such, the tooling aperture 130 in base tool 100may be used to form an aperture 128 substantially in the center of thefeature to be defined by the recess 104 and the feature forming tool110.

In FIG. 5A, a plurality of composite plies 102 are laid up on the basetool 100 over the tooling aperture 130. As shown in FIG. 5B, an apertureforming tool 132, such as a hole punch tool or the like, may be insertedthrough the tooling aperture 130 to form or punch an aperture 128 in thecomposite plies 102 laid up on the base tool 100. For instance, theaperture forming tool 132 has a sharp end 134 a for cutting through theplies 102; the sharp end 134 a is opposite a blunt, distal end 134 b. Astop 136, e.g., an anvil or the like, may be positioned against thecomposite plies 102 opposite the recess 104 a, i.e., against anoutermost surface 102 a of the plies 102. The sharp end 134 a of thetool 132 is driven through the plies and against the stop 136 to formthe aperture 128. The stop 136, for example, helps prevent deformation,tearing, wrinkling, etc. of the plies 102 as the aperture 128 is formedin the plies 102. As such, the stop 136 preferably is of sufficientweight to resist the impact of the aperture forming tool 132 against thestop 136 and has a surface 138 positioned against the plies 102 thatdoes not stick to the plies 102 and does not dull the sharp end 134 a ofthe tool 132. It will be understood that the centerline CL_(A) of theaperture 128 formed by tool 132 is substantially coextensive with thecenterline CL_(T) of the tooling aperture 130, as well as the centerlineCL_(F) of the feature 106. Accordingly, the aperture(s) 128 also mayhelp align a feature forming tool with the composite plies 102, e.g., byaligning a centerline line of each insert 114 with an aperturecenterline CL_(A), the aperture(s) 128 may help align each insert 114 ofthe feature forming tool 110 with the composite plies 102 such that theinserts 114 may properly guide the plies 102 into the base tool recesses104.

FIG. 6 illustrates other exemplary structures for forming an aperture128 in the composite plies 102 laid up on the base tool 100. In someembodiments, a stem 140 having a sharp end 142 is attached to the stop136. The sharp end 142 of the stem 140 is inserted through the plies 102laid up on the base tool 100 and into the tooling aperture 130. Theaperture forming tool 132 fits over the stem 140 and into the toolingaperture 130. A guide tool 144 having a first arm 144 a and a second arm144 b is positioned against the distal end 134 b of the tool 132 and acollar 146 located near the sharp end 142 of the stem 140. The collar146 may not fully surround the stem 140 but, for example, may be aC-shaped clip or the like that partially surrounds the stem. Whenactuated, e.g., when squeezed, the second arm 144 b of the guide tool144 pushes the stem 140 in a second direction D₂ away from the base tool100, and the first arm 144 a of the guide tool 144 pushes the apertureforming tool 132 in a first direction D₁ toward the composite plies 102laid up on the base tool 100. Thus, the guide tool 144 drives the sharpend 134 a of the aperture forming tool 132 against the stop 136, asdescribed above with respect to FIG. 5B, to form the aperture 128 in theplies 102. It will be appreciated that the collar 146, therefore,provides a surface against which the guide tool second arm 144 b can actas the first arm 144 a acts against the distal end 134 b of the apertureforming tool 132 and that the first direction D₁ is substantiallyopposite the second direction D₂.

FIG. 7 provides a flow diagram illustrating a method for formingfeatures in composite components according to an exemplary embodiment ofthe present subject matter. The exemplary method 700 may be used to forma composite component having one or more formed in features, i.e.,features defined in the component without machining the features in thecomponent after processing the composite material 102. As shown at 702in FIG. 7, the exemplary method 700 includes depositing a compositematerial 102 on the base tool 100 having recesses 104, e.g., as shown inFIGS. 3, 3A, and 3B. In some embodiments, the composite material 102 isin the form of a plurality of composite plies 102, which, as generallydescribed above, may be formed from composite tapes having a compositematrix material embedded within a reinforcement material and may be laidup on the base tool 100. In other embodiments, the composite material102 is in a form other than composite plies and, for example, may besprayed or otherwise deposited on the base tool 100.

As illustrated at 704 in FIG. 7, after the composite material 102 isdeposited on the base tool 100, one or more apertures 128 may be formedin the composite material 102 as described with respect to FIGS. 5A, 5B,and 6. For instance, an aperture forming tool 132 may be insertedthrough a tooling aperture 130 in the base tool 100 and then driventhrough the composite material 102 on the base tool 100 and against astop 136. The aperture forming tool 132 may have a sharp end 134 a thatforms an aperture 128 in the composite material 102 as the tool isdriven through the material. In other embodiments, particularly wherethe composite material 102 is a plurality of composite plies, theaperture(s) 128 may be cut in each ply 102 before laying up the plies onthe base tool 100, such that the aperture(s) 128 in each ply 102 arealigned as the plies 102 are laid up on the base tool 100. Further, aspreviously described, the centerline CL_(A) of each aperture 128 may bethe same as the centerline CL_(F) of the respective feature 106, 108,etc. such that the aperture(s) 128 may help align a feature forming toolwith the base tool recess(es) 104.

Next, a feature forming tool 110 is brought into contact with thecomposite material 102, as shown at 706. As described above, the featureforming tool 110 comprises one or more inserts 114 for forming one ormore features of a composite component, such as an engine exhaust linerhaving one or more countersink 106, counterbore 108, locating, or otherfeatures. The feature forming tool 110 is brought into contact with thecomposite material 102 on the base tool 100 such that the inserts 114 ofthe tool 110 push or guide the composite material 102 into the recesses104 defined in the base tool 100, as generally shown in FIGS. 3A and 3B.

Then, as shown at 708 in FIG. 7, a bag 125 may be sealed around thefeature forming tool 110 and the composite material 102, with thefeature forming tool 110 remaining in contact with the compositematerial 102. That is, the feature forming tool 110 and compositematerial 102 may be bagged for processing, e.g., in an autoclave, as isgenerally known in the art. In an exemplary embodiment, bagging the tool110 and composite material 102, with the tool 110 in contact with thecomposite material 102, includes enclosing or encasing the tool 110 andmaterial 102 within a vacuum bag 125, such as a flexible bladder or thelike formed from any suitable material. A vacuum may be drawn within thevacuum bag 125 through a vacuum port connected to a vacuum pump, e.g.,to remove air and volatiles from the material 102. In some embodiments,the bag 125 may be omitted, e.g., where the feature forming tool 110adequately seals the composite material 102 between the feature formingtool 110 and the base tool 100, such that method 700 does not includesealing the bag 125 around the feature forming tool 110 and thecomposite material 102 on the base tool 100.

Next, as depicted at 710 in FIG. 7, the composite material 102 isprocessed, e.g., compacted and autoclaved or, more generally, debulkedand/or processed to reduce porosity, with the feature forming tool 110in contact with the composite material 102. The processed compositematerial forms a green state composite component having the featuresformed by the interaction between the feature forming tool inserts 114and the base tool recesses 104. For example, the green state compositecomponent has been compacted and cured but may retain some solvents usedin forming the composite material and may also contain some voids in thecomposite material. As shown at 712 and 714 in FIG. 7, after processing,the bag 125 (if used) and the feature forming tool 110 are removed fromthe green state composite component, and then the green state compositecomponent undergoes finish processing to produce the composite component90 having one or more features, such as a countersink feature 106 and/ora counterbore feature 108.

Finish processing of the green state component may include one or moreprocesses that may differ from one implementation of method 700 toanother depending on the type of composite material 102. For example,where the composite material 102 is a CMC material, finish processing asshown at 714 in FIG. 7 may include firing (or burn-off) anddensification. More specifically, the green state composite componentmay be fired to produce a fired composite component, e.g., the greenstate composite component, with the bag 125 and/or feature forming tool110 removed, may be placed in a furnace to burn off any solvents used informing the CMC plies and to decompose binders in the solvents. Then,the fired composite component may be densified, e.g., the fired CMCcomponent may be placed in a furnace with silicon to convert a ceramicmatrix precursor of the plies into the ceramic material of the matrix ofthe CMC component. The silicon melts and infiltrates any porositycreated with the matrix as a result of the decomposition of the binderduring burn-off/firing; the melt infiltration of the CMC component withsilicon densifies the CMC component. However, densification may beperformed using any known densification technique including, but notlimited to, Silcomp, melt-infiltration (MI), chemical vapor infiltration(CVI), polymer infiltration and pyrolysis (PIP), and oxide/oxideprocesses. In one embodiment, densification and firing may be conductedin a vacuum furnace or an inert atmosphere having an establishedatmosphere at temperatures above 1200° C. to allow silicon or anotherappropriate material or materials to melt-infiltrate into the component.Optionally, as shown at 716 in FIG. 7, after finish processing thecomposite component may be finish machined, if and as needed, and/orcoated with one or more coatings, such as an environmental barriercoating (EBC) or a thermal barrier coating (TBC).

Turning now to FIGS. 8A, 8B, and 9, other assemblies and methods forforming features in composite components will be described in greaterdetail. As depicted in FIG. 8A, in an exemplary embodiment of thepresent subject matter, a base tool 200 comprises a proximal surface 200a opposite a distal surface 200 b, as well as one or more recesses 204defined in the proximal surface 200 a. A plurality of composite plies102 may be laid up on the proximal surface 200 a of the base tool 200such that the one or more recesses 204 help define one or more featuresof a composite component 90 formed from the plies 102. For example, onerecess 204 may be configured for defining a countersink feature 106 inthe composite component 90 (FIG. 2) while another recess 204 may beconfigured for defining a counterbore feature 108 in the compositecomponent 90 (FIG. 2). Other recesses 204 also may be used to defineadditional and/or different features in the composite component 90, suchas one or more features for locating the composite component within anassembly.

A feature forming tool 210 may be brought into contact with theplurality of composite plies 102 that are supported on the base tool200. The feature forming tool 210 comprises a frame 212 that supportsone or more forming members 214 for forming one or more features of thecomposite component 90. As illustrated in FIG. 8A, the base tool 200 mayinclude one or more alignment features 201 that help align the frame 212and forming members 214 with the base tool 200 and recesses 204. Moreparticularly, the alignment feature(s) 201 may be a wall that projectsaway from the base tool 200, and the frame 212 may comprise a lip 211and a groove 213. When the frame 212 is lowered toward the base tool200, the lip 211 fits against an outer surface 201 a of the alignmentfeature 201 such that the alignment feature 201 is received in thegroove 213. Thus, the frame 212 and base tool 200 may each comprise oneor more features for aligning the feature forming tool 210 with the basetool 200. Moreover, as shown in FIG. 8A, the frame 212 may be secured tothe base tool 200, e.g., using one or more bolts or screws 215, or thelike, to maintain the feature forming tool 210 in position with respectto the base tool 200.

Referring to FIG. 8B, each forming member 214 comprises a shank 216 thatextends through the frame 212 and had a first end 216 a opposite asecond end 216 b. The second end 216 b is located between the frame 212and the plurality of composite plies 102 when the feature forming tool210 is positioned to be brought into contact with the plurality ofcomposite plies 102. In the depicted embodiment, the shank 216 has alength L and a diameter D. Preferably, the ratio of the shank length Lto the shank diameter D is large enough to guide the forming member 214with respect to the composite plies 102. More particularly, the shanklength L should be adequate to guide the forming member 214 as theforming member 214 is deployed to press the composite plies 102 into therecess 204.

Further, each forming member 214 comprises a feature forming head 218 atthe second end 216 b of the shank 216, as well as a biasing member 220positioned between the frame 212 and the feature forming head 218. Thebiasing member 220, such as a spring or the like, urges the featureforming head 218 toward the plurality of composite plies 102 to pressthe plies 102 into the recesses 204. As shown in FIGS. 8A and 8B, therecesses 204 have a shape that is complementary to the shape of thefeature forming heads 218 of the forming members 214 such that,together, the recesses 204 and forming members 214 help define the oneor more features of the composite component 90.

The first end 216 a of the shank 216 extends beyond the frame 212 awayfrom the laid up composite plies 102. A collar 222 encircles orsurrounds the shank first end 216 a, and a nut or other securingmechanism 226 may be used to hold the collar 222 in place on the shank216. A wedge 224 may be positioned between the frame 212 and the collar222, as shown with respect to the leftmost forming member 214 of FIG.8A. The wedge 224 holds the feature forming head 218 away from theplurality of composite plies 102, e.g., until the feature forming tool210 is positioned for lowering the feature forming heads 218 against theplies 102. As one example, each wedge 224 holds the feature forming headaway from the composite plies 102 until the frame 212 is aligned withthe alignment feature(s) 201 of the base tool 200. As illustrated withrespect to the other forming members 214 of FIG. 8A and the enlargedforming member 214 of FIG. 8B, each wedge 224 is positioned within a gapG between the collar 222 and the frame 212. The gap G may be sized suchthat, when the wedge 224 is removed, the feature forming head 218 isurged into contact with the composite plies 102 without applying toomuch force to the plies 102, i.e., without over-squeezing or compactingthe plies 102. That is, the gap G may be sized to allow the featureforming head 218 to displace the composite plies 102 into the recess 204yet limit the amount of force applies to the plies to avoid otherwisedeforming the plies 102. Alternatively or additionally, the biasingmember 220 may be selected or sized to avoid biasing feature formingheads 218 into the composite plies 102 with too much force. For example,where biasing member 220 is a spring, a spring may be selected that hasa spring rate adequate to displace the composite plies 102 into therecess 204 without otherwise deforming the plies 102.

The forming members 214 may be configured in other ways as well. Forexample, the shank 216 may be threaded such that the shank 216 isthreadingly engaged with the frame 212. By turning or rotating the shank216 with respect to the frame 212, the shank 216 may move toward or awayfrom the base tool 200 and the composite plies 102 laid up on the basetool 200. It will be appreciated that the shank 216 may be rotated acertain amount to set the feature forming head 218 to a required depthwith respect to the plies 102 and the base tool 200 such that the head218 does not over-squeeze, compact, or apply too much force to the plies102 as described above. Further, the feature forming head 218 may beattached to the shank 216 such that the head 218 is rotationally freeabout an axis of the shank 216 that extends along the shank length L.That is, the feature forming head 218 may rotate with respect to theshank 216 such that the feature forming head 218 does not twist orotherwise rotationally displace the composite plies 102 as the shank 216is rotated to move the head 218 into contact with the plies 102 and urgethe plies 102 into the recess 204. Other configurations of and means fordisplacing the forming members 214 to press the composite plies 102 intothe base tool recesses 204 may be used as well.

Referring to FIG. 9, a flow diagram is provided that illustrates amethod for forming features in composite components according to anexemplary embodiment of the present subject matter. The exemplary method900 may be used to form a composite component having one or more formedin features, i.e., features defined in the component without machiningthe features in the component after processing the composite material102. As shown at 902 in FIG. 9, the exemplary method 900 includesdepositing a composite material 102 on the base tool 200 having recesses204, e.g., as shown in FIGS. 8A and 8B. In some embodiments, thecomposite material 102 is in the form of a plurality of composite plies102, which, as generally described above, may be formed from compositetapes having a composite matrix material embedded within a reinforcementmaterial and may be laid up on the base tool 200. In other embodiments,the composite material 102 is in a form other than composite plies and,for example, may be sprayed or otherwise deposited on the base tool 200.

As illustrated at 904 in FIG. 9, after the composite material 102 isdeposited on the base tool 200, one or more apertures 128 may be formedin the composite material 102 as described with respect to FIGS. 5A, 5B,and 6. For instance, an aperture forming tool 132 may be insertedthrough a tooling aperture (not shown) in the base tool 200 and thendriven through the composite material 102 on the base tool 200 andagainst a stop 136. The aperture forming tool 132 may have a sharp end134 a that forms an aperture 128 in the composite material 102 as thetool is driven through the material. In other embodiments, particularlywhere the composite material 102 is a plurality of composite plies, theaperture(s) 128 may be cut in each ply 102 before laying up the plies onthe base tool 200, such that the aperture(s) 128 in each ply 102 arealigned as the plies 102 are laid up on the base tool 200. Further, aspreviously described, the centerline CL_(A) of each aperture 128 may bethe same as the centerline CL_(F) of the respective feature 106, 108,etc. such that the aperture(s) 128 may help align a feature forming toolwith the base tool recess(es) 104.

In some embodiments, a bag, similar to the bag 125 shown in FIGS. 3A and3B, then may be sealed around the composite material 102, as shown at906 in FIG. 9. That is, the composite material 102 may be bagged forprocessing, e.g., in an autoclave, as is generally known in the art. Forexample, bagging the composite material 102 includes enclosing orencasing the material 102 within a vacuum bag, such as a flexiblebladder or the like formed from any suitable material. A vacuum may bedrawn within the vacuum bag through a vacuum port connected to a vacuumpump, e.g., to remove air and volatiles from the composite material 102.In some embodiments, the bag may be omitted, such that method 900 doesnot include sealing the bag 125 around the composite material 102 on thebase tool 200.

Next, as shown at 908, a feature forming tool 210 is deployed to pressthe composite material 102 into the base tool recesses 204 to formfeatures of the composite component. More particularly, the featureforming tool 210 is brought into contact with the bag that is sealedaround the composite material 102 or, if the bag is omitted, is broughtinto contact with the composite material 102 on the base tool 200. Asdescribed above, the feature forming tool 210 comprises a frame 212supporting one or more forming members 214 for forming one or morefeatures of the composite component 90. The frame 212 may be alignedwith the base tool 200 using the alignment feature(s) 201 of the basetool 200 such that the feature forming head 218 of each forming member214 can be lowered onto the vacuum bag that is over the compositematerial 102 or directly onto the composite material 102 to guide thematerial 102 into the recesses 204 of the base tool 200. The featureforming heads 218 may be lowered, e.g., by removing the wedges 224 thathold the heads 218 away from the composite material 102 such thatbiasing members 220 urge the heads 218 into contact with the compositematerial 102, directly or indirectly through the vacuum bag, asdescribed above. In other embodiments, the shank 216 of each formingmember 214 may be rotated to lower the feature forming heads 218 andbring the heads 218 into direct or indirect contact with the compositematerial 102, as previously described in greater detail.

Then, as depicted at 910 in FIG. 9, the plurality of composite material102 is processed, e.g., compacted and autoclaved or, more generally,debulked and/or processed to reduce porosity, with the feature formingtool 210 pressing the composite material 102 into the base tool recesses204. The processed composite material forms a green state compositecomponent having the features formed by the interaction between theforming members 214 and the base tool recesses 204. As shown at 912 and914 in FIG. 9, after processing, the bag (if used) and the featureforming tool 210 are removed from the green state composite component,and then the green state composite component undergoes finish processingto produce the composite component 90 having one or more features, suchas a countersink feature 106 and/or a counterbore feature 108. Asdescribed above with respect to method 700 illustrated in FIG. 7, finishprocessing of the green state composite component may include one ormore processes that may differ depending on the type of compositematerial 102 used in the method 900. In one embodiment, where thecomposite material 102 is a CMC material, finish processing at 914 inFIG. 9 includes firing (or burn-off) of the green state compositecomponent to produce a fired composite component, followed bydensification of the fired composite component to produce the compositecomponent. The firing and densification processes may be similar tothose described above with respect to method 700. Further, as shown at916 in FIG. 9, after finish processing the composite componentoptionally may be finish machined, if and as needed, and/or coated withone or more coatings, such as an environmental barrier coating (EBC) ora thermal barrier coating (TBC).

Turning now to FIGS. 10A through 11F, other assemblies and methods forforming features in composite components will be described in greaterdetail. As depicted in FIG. 10A, in an exemplary embodiment of thepresent subject matter and similar to the embodiments illustrated inFIGS. 3, 3A, 3B, 8A, and 8B, a base tool 300 comprises a proximalsurface 300 a opposite a distal surface 300 b, as well as one or morerecesses 304 defined in the proximal surface 300 a. A plurality ofcomposite plies 102 may be laid up on the proximal surface 300 a of thebase tool 300 such that the one or more recesses 304 help define one ormore features of a composite component 90 formed from the plies 102. Forinstance, one recess 304 may be configured for defining a countersinkfeature 106 in the composite component 90 (FIG. 2) while another recess304 may be configured for defining a counterbore feature 108 in thecomposite component 90 (FIG. 2). Other recesses 304 also may be used todefine additional and/or different features in the composite component90, such as one or more locating or other features.

A feature forming tool 310 may be brought into contact with theplurality of composite plies 102 that are supported on the base tool 300by inserting the feature forming tool 310 through an aperture 128 formedin the plies 102 as described above with respect to FIGS. 5A, 5B, and 6.More particularly, the feature forming tool 310 comprises a stem 312 anda feature forming head 314. The stem has a head end 312 a opposite a tipend 312 b; the feature forming head 314 extends from the head end 312 a.The stem 312 and feature forming head 314 may be integrally formed as asingle piece feature forming tool 310, or the feature forming head 314may be attached or coupled to the stem 312. The feature forming head 314has a shape that is complementary to the shape of the recess 304 of thebase tool 300 such that, together, the recess 304 and feature forminghead 314 help define the one or more features of the composite component90.

As illustrated in the exemplary embodiment of FIGS. 10A, 10B, and 10C,the feature forming head 314 includes a cap 315 formed from a firstmaterial 316, while the remainder of the feature forming tool 310 isformed from a second material 318. As previously described with respectto first and second materials 116, 118, the second material 318 may beharder than the first material 316. In exemplary embodiments, the firstmaterial 316 is silicone, such that the cap 315 is formed from siliconeand the remainder of the feature forming head 314 and the stem 312 areformed from a material 318 that is harder than silicone, e.g., a metal,polymer, or elastomer having a greater Shore hardness than silicone. Asfurther illustrated in FIGS. 10A, 10B, and 10C, the cap 315 preferablyhas a narrow edge 315 a defining the largest perimeter of the featureforming head 314. The narrow edge 315 a is positioned at a transitionarea 320 between a portion of the composite plies 102 pressed into therecess 304 by the feature forming head 314 and a portion of thecomposite plies 102 that are laid up on base tool 300 without beingpressed into a recess 304. The relatively softer first material 316 fromwhich the cap 315 is formed may help the composite plies 102 smoothlytransition into the recess 304 in the transition area 320, e.g., the cap315 may help prevent crimping, wrinkling, or the like of the plies 102around the feature forming tool 310. Further, the narrow edge 315 ahelps keep the composite plies 102 smooth where a bag is sealed over theplies 102 as described in greater detail below.

Referring particularly to FIG. 10C, the base tool 300 includes a toolingaperture 330 extending from the distal surface 300 b of the base tool300 to the recess 304, similar to the tooling aperture 130 describedabove with respect to FIGS. 5A, 5B, and 6. More particularly, thetooling aperture 330 extends from a distal end 330 b at the base tooldistal surface 300 b to a proximal end 330 a at the recess 304, and thetooling aperture 330 has a centerline CL_(T). As shown in FIG. 10C, thefeature forming tool 310 is centered along the tooling aperturecenterline CL_(T) and the aperture centerline CL_(A) such that thefeature centerline CL_(F) is co-extensive with or aligned along thetooling aperture and composite aperture centerlines CL_(T), CL_(A). Itwill be appreciated that the tooling aperture 330 in base tool 300 maybe used to form an aperture 128 substantially in the center of thefeature to be formed by the recess 304 and the feature forming tool 310.Moreover, as described above, where the centerline CL_(A) of eachaperture 128 is substantially the same as the centerline CL_(F) of therespective feature 106, 108, etc., the aperture(s) 128 may help alignthe feature forming tool 310 with the base tool recess(es) 304.

Further, in some embodiments of the present subject matter, a seal 322,such as an O-ring or the like, is positioned in the tooling aperture 330adjacent the recess 304, e.g., to provide a seal around the stem 312 ofthe feature forming tool 310. More specifically, in some embodiments,the pre-preg composite plies 102 may be at least partially wet, e.g.,the slurry composition impregnating the fibers may be at least partiallyliquid or fluidic. As such, the slurry may tend to flow into the toolingaperture 330, particularly when the feature forming tool 310 is broughtinto contact with the composite plies 102 to press the plies into therecess 304. The seal 322 helps prevent the slurry or other constituentsof the pre-preg from oozing, running, dripping, or otherwise travelinginto the tooling aperture 330 as the feature forming tool 310 pressesthe composite plies 102 into the recess 304.

FIGS. 11A through 11F illustrate another assembly for forming featuresin a composite component according to an exemplary embodiment of thepresent subject matter. As shown in FIG. 11A, a plurality of compositeplies 102 may be laid up on a proximal side 300 a of base tool 300 asdescribed with respect to FIGS. 10A, 10B, and 10C. The base tool 300comprises a recess 304, as well as a tooling aperture 330 that extendsfrom a proximal end 330 a at the recess 304 to a distal end 330 b at thebase tool distal surface 300 b. The composite plies 102 are laid up onthe base tool 300 such that the plies 102 overlay the recess 304.

As depicted in FIG. 11B, an aperture forming tool 332 may be used toform an aperture 128 in the composite plies 102 supported on the basetool 300. More particularly, the aperture forming tool 332 may be an awlor the like that is inserted into the distal end 330 b of the toolingaperture 330. A sharp end 332 a of the tool 332 pierces the plurality ofcomposite plies 102 as the aperture forming tool 332 is inserted throughthe tooling aperture 330, and a shaft 334 of the tool 332 forms theaperture 128 as the tool shaft 334 is inserted through the plies 102. Ahandle end 332 b of the tool 332, opposite the sharp end 332 a, providesan area to grip the aperture forming tool 332 for manipulation, e.g.,insertion into and through the tooling aperture 330 and into theplurality of composite plies 102.

Referring to FIG. 11C, in the depicted embodiment, the sharp end 332 aof the aperture forming tool 332 is removable. As such, after the sharpend 332 a pierces the composite plies 102 and the shaft 334 is insertedthrough the plies 102 to form the aperture 128 in the plies, the sharpend 332 a is removed while the shaft 334 of the aperture forming tool332 remains in contact with the plies 102. Then, as shown in FIG. 11D,the feature forming tool 310 is attached to the shaft 334 of the tool332. That is, the tip end 312 b of the feature forming tool stem 312 isconfigured to be attached to the shaft 334 of the aperture forming tool332. The aperture forming tool 332 then is retracted or drawn backthrough the tooling aperture 330 to move the feature forming tool 310into contact with the plurality of composite plies 102. In particular,the stem 312 of the feature forming tool 310 is guided into the toolingaperture 330 in the base tool 300, and the feature forming head 314guides the composite plies 102 into the recess 304 until the plies 102and the head 314 are seated within the recess 304. It will beappreciated that the feature forming head 314 may be configured asdescribed above with respect to FIGS. 10A, 10B, and 10C, e.g., thefeature forming head 314 may comprise a cap 315 formed from a firstmaterial 316 and having a narrow edge 315 a while the remainder of thehead 314 is formed from a second material 318.

Once the plurality of composite plies 102 are guided into the recess 304such that the plies 102 are trapped between the base tool 300 and thefeature forming tool 310, the aperture forming tool 332 is detached. Asshown in FIG. 11E, the feature forming tool 310 remains in contact withthe composite plies 102 after the aperture forming tool 332 is detachedfrom the feature forming tool 310. Finally, in some embodiments, a bag125 may be sealed around the composite plies 102 with the featureforming tool 310 in contact with the plies 102 as illustrated in FIG.11F. The plurality of composite plies 102 and the feature forming tool310 may then be processed as described in greater detail below.

Using the aperture forming tool 332 to guide the feature forming tool310 into contact with the plurality of composite plies 102 may behelpful in some embodiments of the present subject matter. For instance,as described above, the composite plies 102 generally may be wet orsticky, e.g., due to the slurry used to form prepreg plies, which maymake it difficult to guide the feature forming tool 310 through theaperture 128 in the plies 102 and into the tooling aperture 330.Accordingly, attaching the feature forming tool 310 to the apertureforming tool 332 that is already positioned within the aperture 128 andthe tooling aperture 330 can simplify guiding the feature forming tool310 into position with respect to the plies 102 and the base tool 300.However, in other embodiments, the sharp end 332 a of the apertureforming tool 332 may not be removable. In such embodiments, the apertureforming tool 332 may be used to form the aperture 128 in the compositeplies 102, as generally described above, and then the tool 332 may beremoved from the plies 102 and base tool 300, e.g., by retracting thetool 332 through the tooling aperture 330. Next, the feature formingtool 310, without being attached to the aperture forming tool 332, maybe inserted through the composite plies 102 and into the base tool 300until the feature forming head 314 guides the plies 102 into the basetool recess 304 to seat the plies 102 and head 314 in the recess 304.The assembly, i.e., the tool 310 and plies 102, then may be baggedand/or processed as described in greater detail below.

Turning to FIG. 12, a flow diagram is provided that illustrates a methodfor forming features in composite components according to an exemplaryembodiment of the present subject matter. The exemplary method 1200 maybe used to form a composite component having one or more formed infeatures, i.e., features defined in the component without machining thefeatures in the component after processing the composite material 102.As shown at 1202 in FIG. 12, the exemplary method 1200 includesdepositing a composite material 102 on the base tool 300 having recesses304, e.g., as shown in FIGS. 10A through 11F. In some embodiments, thecomposite material 102 is in the form of a plurality of composite plies102, which, as generally described above, may be formed from compositetapes having a composite matrix material embedded within a reinforcementmaterial and may be laid up on the base tool 300. In other embodiments,the composite material 102 is in a form other than composite plies and,for example, may be sprayed or otherwise deposited on the base tool 300.

As illustrated at 1204 in FIG. 12, after the composite material 102 isdeposited on the base tool 300, one or more apertures 128 may be formedin the composite material 102. In one embodiment of method 1200, theapertures 128 may be formed as described with respect to FIGS. 5A, 5B,and 6. For instance, an aperture forming tool 132 may be aligned with atooling aperture 330 in the base tool 300, inserted into the toolingaperture 330 through the distal end 330 b, and then driven through thecomposite material 102 on the base tool 300. The aperture forming tool132 may have a sharp end 134 a that forms an aperture 128 in thecomposite material 102 as the tool is driven through the material.Finally, the tool 132 is removed from the composite material 102,leaving the aperture 128 in the material 102. In other embodiments,particularly where the composite material 102 is a plurality ofcomposite plies, the aperture(s) 128 may be cut in each ply 102 beforelaying up the plies on the base tool 300, such that the aperture(s) 128in each ply 102 are aligned as the plies 102 are laid up on the basetool 300. Further, as previously described, the centerline CL_(A) ofeach aperture 128 may be the same as the centerline CL_(F) of therespective feature 106, 108, etc. such that the aperture(s) 128 may helpalign a feature forming tool with the base tool recess(es) 304.

Next, as shown at 1206 in FIG. 12, a feature forming tool 310 isdeployed to press the composite material 102 into the base tool recesses304 to form features of the composite component. More particularly, asshown in FIGS. 10A, 10B, and 10C, a tip end 312 b of a stem 312 of thefeature forming tool 310 is inserted into the aperture 128 formed in thecomposite material 102 such that the stem 312 is inserted through thecomposite material 102 and into the tooling aperture 330 of the basetool 300. The stem 312 thereby aligns the feature forming head 314 ofthe tool 310 with the base tool recess 304. As such, as the stem 312 isdrawn through the tooling aperture 330 and the feature forming head 314is brought into contact with the composite material 102, the featureforming head 314 guides and presses the composite material 102 into therecess 304. The stem 312 may be drawn into the tooling aperture 330until the edge 315 a of the feature forming head cap 315 contacts anoutermost surface 102 a of the composite material 102 supported on thebase tool 300. An innermost surface 102 b of the composite material 102contacts the proximal surface 300 a of the base tool 300.

In other embodiments of method 1200, the apertures 128 may be formed andthe feature forming tool 310 brought into contact with the compositematerial 102 as described with respect to FIGS. 11A through 11F. Forexample, to form an aperture 128 in the composite material 102 on thebase tool 300 as shown at 1204 in FIG. 12, an aperture forming tool 332having a removable sharp end 332 a is aligned with the tooling aperture330 in base tool 300. The tool 332 is inserted into the tooling aperture330 through distal end 330 b until the aperture forming tool sharp end332 a pierces through the composite material 102 and a shaft 334 of thetool 332 forms the aperture 128. Then, the sharp end 332 a is removedfrom the shaft 334 and the feature forming tool 310 is attached to theshaft 334 of the aperture forming tool 332. Next, as shown at 1206 inFIG. 12, the aperture forming tool 332 is drawn back through the toolingaperture 330 to deploy the feature forming tool 310 to press thecomposite material 102 into the base tool recesses 304 to form featuresof the composite component. Once the composite material 102 and thefeature forming head 314 are seated within the recess 304 as shown inFIG. 11E, the aperture forming tool 332 is detached from the featureforming tool 310, with the edge 315 a of the feature forming head cap315 contacting an outermost surface 102 a of the composite material 102,which has an innermost surface 102 b in contact with the proximalsurface 300 a of the base tool 300.

As shown at 1208 in FIG. 12, in some embodiments of method 1200, a bag125 may be sealed around the composite material 102 with the featureforming tool 310 in contact with the composite material, as illustratedin FIGS. 10B and 11F. That is, the composite material 102 may be baggedfor processing with the feature forming tool 310 in contact with thematerial 102. For example, bagging the composite material 102 includesenclosing or encasing the material 102 and feature forming tool 310within a vacuum bag, such as a flexible bladder or the like formed fromany suitable material. A vacuum may be drawn within the vacuum bagthrough a vacuum port connected to a vacuum pump, e.g., to remove airand volatiles from the composite material 102. In some embodiments, thebag may be omitted, such that method 1200 does not include sealing thebag 125 around the composite material 102 on the base tool 300 with thefeature forming tool 310 in contact with the composite material.

Then, as depicted at 1210 in FIG. 12, the composite material 102 isprocessed, e.g., compacted and autoclaved or, more generally, debulkedand/or processed to reduce porosity, with the feature forming tool 310pressing the composite material 102 into the base tool recess 304. Theprocessed composite material forms a green state composite componenthaving the features formed by the interaction between the featureforming head 314 and the base tool recess 304. As shown at 1212 and 1214in FIG. 12, after processing, the bag (if used) and the feature formingtool 310 are removed from the green state composite component, and thenthe green state composite component undergoes finish processing toproduce the composite component 90 having one or more features, such asa countersink feature 106 and/or a counterbore feature 108. As describedabove with respect to method 700 illustrated in FIG. 7, finishprocessing of the green state composite component may include one ormore processes that may differ depending on the type of compositematerial 102 used in the method 1200. In one embodiment, where thecomposite material 102 is a CMC material, finish processing at 1214 inFIG. 12 includes firing (or burn-off) of the green state compositecomponent to produce a fired composite component, followed bydensification of the fired composite component to produce the compositecomponent. The firing and densification processes may be similar tothose described above with respect to method 700. Further, as shown at1216 in FIG. 12, after finish processing the composite componentoptionally may be finish machined, if and as needed, and/or coated withone or more coatings, such as an environmental barrier coating (EBC) ora thermal barrier coating (TBC).

Referring now to FIG. 13, in some embodiments, a tooling assembly isused with the base tool to support a part to be embedded into thecomposite material. For instance, as illustrated in FIG. 13, a base tool400 comprises a proximal surface 400 a opposite a distal surface 400 b,and a plurality of composite plies 102 may be laid up on the proximalsurface 400 a of the base tool 400. An aperture 128 may be formed in thecomposite plies 102 supported on the base tool 400, e.g., as describedabove with respect to FIGS. 5A, 5B, and 6.

Further, a feature forming tool 410 may be brought into contact with theplurality of composite plies 102 that are supported on the base tool400. More particularly, a tooling assembly 412 is attached to the basetool 400 such that a pin 414 may be inserted into the aperture 128 andmaintained in contact with the composite plies 102, i.e., the toolingassembly 412 prevents the pin 414 from dropping through the base tool400. In some embodiments, the pin 414 is configured to be embedded inthe composite component 90, e.g., the pin 414 may be formed from amaterial that integrates with the composite material as the compositematerial is transformed into the composite component 90. For instance,where the composite plies 102 are CMC plies 102, the pin 414 may beformed from a ceramic material such that the ceramic pin 414 is embeddedin the composite component 90. Where the composite material 102 is a PMCmaterial 102, the pin 414 may be formed from a metallic material, suchas a metal or metal alloy. In other embodiments, the pin 414 isconfigured to be removed after processing of the composite material,such that the pin 414 is not embedded in the composite component 90 butis used to form a void feature, such as an aperture 128, in thecomponent 90.

The tooling assembly 412 comprises a shoulder bushing 416 positioned ina passage 418 in the base tool 400. The shoulder bushing 416 has a firstend 416 a opposite a second end 416 b and defines an opening 420therethrough. The first end 416 a is adjacent the plurality of compositeplies 102 laid up on the base tool 400, and the second end 416 b extendsthrough the base tool 400 and defines a shoulder 422 that rests on aboss 424 of the base tool 400. The boss 424 extends from the base tooldistal surface 400 b. In the exemplary embodiment of FIG. 13, the boss424 is threaded, and a nut 425 is threaded onto the boss 424 to hold theshoulder 422 of the shoulder bushing 416 against the boss 424. However,the shoulder bushing 416 may be secured to the base tool 400 in otherways as well, e.g., another securing mechanism 425 than a nut may beused to secure the shoulder bushing 416 to the base tool 400. Moreover,an end cap 426 is secured to the second end 416 b of the shoulderbushing 416 to cover and/or plug the opening 420 at the second end 416b. As shown in the depicted exemplary embodiment, the end cap 426 may bethreaded to a threaded projection 428 extending from the shoulderbushing second end 416 b, but the end cap 426 may have otherconfigurations or may be otherwise secured to the shoulder bushing 416.It will be appreciated that the pin 414 may be inserted through theaperture 128 in the composite plies 102 and into the shoulder bushingopening 420 after the end cap 426 is secured in place at the second end416 b of the shoulder bushing 416 such that the end cap 426 prevents thepin 414 from dropping through the opening 420 at the second end 416 band out of contact with the plies 102.

The tooling assembly 412 and pin 414 configuration may be particularlyuseful where the composite component 90 comprises several pins 414 thatextend along different vectors. For instance, the base tool 400 maycomprise several passages 418, e.g., two or more passages 418, that eachreceive a tooling assembly 412 and a pin 414 such that several pins 414may be embedded in the composite component 90 formed from a plurality ofcomposite plies 102 laid up on the base tool 400. In some embodiments,one passage 418 and the pin 414 positioned therein may be aligned alonga different vector than another passage 418 and pin 414, and in otherembodiments, each passage 418 and its respective pin 414 may be alignedalong a different vector than the other passages 418 and pins 414 of thebase tool 400 and lay up. The differing orientations of the pins 414could make it difficult to remove the composite component from the basetool 400. However, the tooling assembly 412 permits the shoulderbushings 416 to be removed from the passages 418, e.g., by removing thenuts or securing mechanisms 425 holding the shoulder bushings 416 to thebase tool 400, to expose larger openings (the passages 418) for the pins414 to move within as the composite component is removed from the basetool 400. The larger openings of the passages 418 allow the pins 414 agreater range of movement with respect to the base tool 400 such that acomposite component having a more complicated pin arrangement, e.g.,pins 414 extending along several different vectors, can be removed fromthe base tool 400.

As further illustrated in FIG. 13, the feature forming tool 410comprises a thin disk, such that bringing the feature forming tool 410into contact with the plurality of composite plies 102 comprises placingthe disk 410 over the pin 414 and against the plurality of compositeplies 102. Similar to the feature forming head 314 described withrespect to FIGS. 10A, 10B, and 10C, the thin, disk-shaped featureforming tool 410 may comprise an edge portion 410 a formed from a firstmaterial 428 and a body portion 410 b formed from a second material 430.As previously described with respect to first and second materials 116,118, the second material 430 may be harder than the first material 428.In exemplary embodiments, the first material 428 is silicone, such thatthe edge portion 410 a is formed from silicone and the remainder of thefeature forming tool 410 (i.e., body portion 410 b) is formed from amaterial 430 that is harder than silicone, e.g., a metal, polymer, orelastomer having a greater Shore hardness than silicone. As furtherillustrated in FIG. 13, the edge portion 410 a preferably is relativelynarrow or thin and defines the largest perimeter of the feature formingtool 410. The narrow edge portion 410 a helps form a transition area 429between the composite plies 102 and the bag 125 sealed around the plies102 and the tool 410 as further described below. The relatively softerfirst material 428 from which the edge portion 410 a is formed may helpprevent crimping, wrinkling, or the like of the composite plies 102around the feature forming tool 410, keeping the composite plies 102smooth where the bag 125 is sealed over the plies 102.

Turning to FIG. 14, in other embodiments of the present subject matter,the tooling assembly 412 may comprise different configurations. Forexample, in the embodiment depicted in FIG. 14, the tooling assembly 412is configured for receipt of a removable feature forming tool 410 ratherthan a pin 414 to be embedded in the composite component 90. Theillustrated tooling assembly 412 comprises a female die 432 that definesa recess 404, similar to the recesses 104, 204, 304 defined in the basetools 100, 200, 300 described above, and defines an opening 434therethrough. As such, the female die 432 is shaped complementary to thefeature forming tool 410, which forms a male die with a feature forminghead 436 shaped complementary to the recess 404 and a stem 438 thatextends into the opening 434 in female die 432 when the feature formingtool 410 is positioned in the tooling assembly 412. It will beappreciated that, similar to the shoulder bushing 416 described withrespect to FIG. 14, the female die 432 may be positioned within apassage 418 defined in the base tool 400, although the passage 418 thatreceives a female die 432 may have a different size and/orcross-sectional shape than the passage 418 that receives a shoulderbushing 416. Further, as illustrated in FIG. 14, a seal 440, such as anO-ring or the like, is received in a groove 442 defined in the femaledie 432 to provide a seal between the female die 432 and the base tool400, e.g., to help prevent slurry from the prepreg composite plies frompassing through the passage 418 in the base tool 400.

The tooling assembly 412 also includes a nut 444 that threadinglyengages the female die 432 adjacent the distal surface 400 b of the basetool 400 to hold the female die 432 within the base tool 400. In otherembodiments, a securing mechanism 444 other than a nut may be used tohold the female die 432 in place with respect to the base tool 400.Moreover, the tooling assembly 412 includes a sleeve 446 that isreceived in a distal portion 434 b of the opening 434 through the femaledie 432. As shown in FIG. 14, a proximal portion 434 a of the opening434 is sized such that the opening 434 closely surrounds the stem 438 ofthe feature forming tool 410. The distal portion 434 b is sized toreceive the sleeve 446, which defines an opening 448 therein throughwhich the stem 438 passes. A seal 450, such as an O-ring or the like, ispositioned between a proximal end 446 a of the sleeve 446 and the femaledie 432, e.g., to provide a seal around the stem 438 of the featureforming tool 410. A nut 452 threadingly engages the female die 432 tocapture and maintain the sleeve 446 within the distal portion 434 b ofthe die opening 434. Of course, in other embodiments, a securingmechanism 452 other than a nut may be used to secure the sleeve withinthe opening 434.

It will be understood that the feature forming head 436 of the featureforming tool 410 shown in FIG. 14 guides and presses the compositematerial 102 into the recess 404 similar to the feature forming head 314described with respect to FIGS. 10A through 11F. Further, like featureforming head 314, the feature forming head 436 of FIG. 14 may comprise acap and/or edge formed from a first material, such as silicone, whilethe remainder of the head 436 is formed from a second material having agreater Shore hardness than the first material. In other embodiments,the feature forming head 436 may be formed entirely from the firstmaterial or the second, harder material. However, the first, softermaterial may be preferable, at least around the edge of the featureforming head where the composite plies 102 transition into the recess404, e.g., to prevent crimping, wrinkling, or the like of the plies 102around the feature forming tool 410 and/or to help keep the plies 102smooth where a bag is sealed over the plies 102 as described in greaterdetail below.

FIG. 15 provides a flow diagram illustrating a method for formingfeatures in composite components according to an exemplary embodiment ofthe present subject matter. The exemplary method 1500 may be used toform a composite component having one or more formed in features, i.e.,features defined in the component without machining the features in thecomponent after processing the composite material 102. As shown at 1502in FIG. 15, the exemplary method 1500 comprises assembling a toolingassembly 412 with a base tool 400, as described with respect to FIGS. 13and 14. In some embodiments, as depicted in FIG. 13, the toolingassembly 412 is assembled with the base tool 400 by inserting a shoulderbushing 416 into a passage 418 defined in the base tool 400. Then, a nutor other securing mechanism 425 is used to secure the shoulder bushing416 to the base tool 400. For example, a nut 425 is threaded onto athreaded boss 424 defined by the base tool 400 to trap a shoulder 422 ofthe shoulder bushing 416 between the nut 425 and the boss 424 andthereby secure the shoulder bushing 416 to the base tool 400. Next, anend cap 426 is secured at the second end 416 b of the shoulder bushing416 to cover or stop up an opening in the shoulder bushing 416 at itssecond end 416 b.

In other embodiments, as illustrated in FIG. 14, the tooling assembly412 is assembled with the base tool 400 by inserting a female die 432into the passage 418 defined in the base tool 400. A nut or othersecuring mechanism 444 secures the female die 432 to the base tool 400.Then, a sleeve 446, which defines an opening 448 therethrough, isinserted into a distal portion 434 b of an opening 434 through thefemale die 432. A nut or other securing mechanism 452 secures the sleeve446 within the opening 434 in the female die 432. One or more seals 440,450, such as O-ring seals or the like, may be used between the femaledie 432 and the base tool 400 and/or between the sleeve 446 and thefemale die 432.

As depicted at 1504 in FIG. 15, the exemplary method 1500 also includesdepositing a composite material 102 on the base tool 400 and toolingassembly 412, e.g., as shown in FIGS. 13 and 14. In some embodiments,the composite material 102 is in the form of a plurality of compositeplies 102, which, as generally described above, may be formed fromcomposite tapes having a composite matrix material embedded within areinforcement material and may be laid up on the base tool 400. In otherembodiments, the composite material 102 is in a form other thancomposite plies and, for example, may be sprayed or otherwise depositedon the base tool 400.

As illustrated at 1506 in FIG. 15, after the composite material 102 isdeposited on the base tool 400, one or more apertures 128 may be formedin the composite material 102. In one embodiment of method 1500, theapertures 128 may be formed as described with respect to FIGS. 5A, 5B,and 6. For instance, referring to FIG. 13, an aperture forming tool 132may be aligned with the opening 420 through the shoulder bushing 416 andthen driven through the composite material 102 on the base tool 400. Theaperture forming tool 132 may have a sharp end 134 a that forms anaperture 128 in the composite material 102 as the tool is driven throughthe material. Finally, the tool 132 is removed from the compositematerial 102, leaving the aperture 128 in the material 102. In otherembodiments, the aperture forming tool 132 may be used to form theaperture 128 before the end cap 426 is positioned on the second end 416b of the shoulder bushing 416. For example, the aperture forming tool132 may be aligned with the opening 420, inserted through the opening420 at the second end 416 b of the shoulder bushing 416, and driventhrough the composite material 102 and against a stop 136 to form anaperture 128 as described with respect to FIGS. 5A and 5B. In stillother embodiments, a guide tool 144 may be used to form the aperture 128as described with respect to FIG. 6. After the aperture 128 is formed inthe composite material 102, the end cap 426 may be secured to theshoulder bushing 416 as described above. Further, it will be appreciatedthat the aperture 128 also may be formed as described with respect toFIGS. 11A through 11F, and for the embodiment shown in FIG. 14, anaperture 128 may be formed in the composite material 102 as describedwith respect to FIG. 5A, 5B, 6, or 11A through 11F. In yet otherembodiments, particularly where the composite material 102 is aplurality of composite plies, the aperture(s) 128 may be cut in each ply102 before laying up the plies on the base tool 400, such that theaperture(s) 128 in each ply 102 are aligned as the plies 102 are laid upon the base tool 400. Moreover, as previously described, the centerlineCL_(A) of each aperture 128 may be the same as the centerline CL_(F) ofthe respective feature 106, 108, etc. such that the aperture(s) 128 mayhelp align a feature forming tool with the base tool recess(es) 104.

Next, as shown at 1508 in FIG. 15, a feature forming tool 410 isdeployed to press a pin 414 in place, as described with respect to FIG.13, or to press the composite material 102 into the recess 404, asdescribed with respect to FIG. 14, and thereby form one or more featuresof the composite component. More particularly, as shown in the exemplaryembodiment of FIG. 13, deploying the feature forming tool 410 comprisesinserting a pin 414 through the aperture 128 in the composite material102 and into the opening 420 in the shoulder bushing 416 and thenplacing a generally disk-shaped feature forming tool 410 over the pin414. Alternatively, as shown in the exemplary embodiment of FIG. 14,deploying the feature forming tool 410 comprises inserting a stem 438 ofthe feature forming tool 410 into the aperture 128 formed in thecomposite material 102 such that the stem 438 is inserted through thematerial 102 and into the opening 434 in the female die 432. The stem438 thereby aligns the feature forming head 436 of the tool 410 with therecess 404 defined in the female die 432. As such, as the stem 438advances through the opening 434 and the feature forming head 436 isbrought into contact with the composite material 102, the featureforming head 436 guides and presses the composite material 102 into therecess 404. The stem 438 may be drawn into the opening 434 until an edgeof the feature forming head 436 contacts an outermost surface 102 a ofthe composite material 102 supported on the base tool 400. An innermostsurface 102 b of the composite material 102 contacts the proximalsurface 400 a of the base tool 400.

As shown at 1510 in FIG. 15, in some embodiments of method 1500, a bag125 may be sealed around the composite material 102 with the featureforming tool 410 in contact with the composite material, as illustratedin FIGS. 13 and 14. That is, the composite material 102 may be baggedfor processing with the feature forming tool 410 in contact with thematerial 102. For example, bagging the composite material 102 includesenclosing or encasing the material 102 and feature forming tool 410within a vacuum bag, such as a flexible bladder or the like formed fromany suitable material. A vacuum may be drawn within the vacuum bagthrough a vacuum port connected to a vacuum pump, e.g., to remove airand volatiles from the composite material 102. In some embodiments, thebag may be omitted, such that method 1500 does not include sealing thebag 125 around the composite material 102 on the base tool 400 with thefeature forming tool 410 in contact with the composite material.

Then, as depicted at 1512 in FIG. 15, the composite material 102 isprocessed, e.g., compacted and autoclaved or, more generally, debulkedand/or processed to reduce porosity, with the feature forming tool 410in contact with the composite material 102. The processed compositematerial forms a green state composite component having the featuresformed by, e.g., the pin 414 embedded therein or the interaction betweenthe feature forming head 436 and the recess 404. As shown at 1514 and1516 in FIG. 15, after processing, the bag (if used) and the featureforming tool 410 are removed from the green state composite component,and then the green state composite component undergoes finish processingto produce the composite component 90 having one or more features, suchas an embedded pin 414, a countersink feature 106, and/or a counterborefeature 108. As described above with respect to method 700 illustratedin FIG. 7, finish processing of the green state composite component mayinclude one or more processes that may differ depending on the type ofcomposite material 102 used in the method 1500. In one embodiment, wherethe composite material 102 is a CMC material, finish processing at 1516in FIG. 15 includes firing (or burn-off) of the green state compositecomponent to produce a fired composite component, followed bydensification of the fired composite component to produce the compositecomponent. The firing and densification processes may be similar tothose described above with respect to method 700. Further, as shown at1518 in FIG. 15, after finish processing the composite componentoptionally may be finish machined, if and as needed, and/or coated withone or more coatings, such as an environmental barrier coating (EBC) ora thermal barrier coating (TBC).

FIGS. 16A and 16B illustrate other tooling assemblies that may be usedto form one or more features in a composite component. In the depictedembodiments, the tooling assembly 500 includes a main tool 502 and asegmented tool 504 that comprises two or more segments. A first segment504 a is shown in FIGS. 16A and 16B, but it will be appreciated that thesegmented tool 504 also includes a second segment and may also includeadditional segments, e.g., a third, fourth, fifth segment and so on. Asillustrated in FIGS. 16A and 16B, the tooling assembly 500 may be usedto form axisymmetric composite components having an axial centerlineACL_(C). As such, features formed in the composite component that extendaway from the centerline ACL_(C) may hinder removal of the componentfrom a tool or mold on which the composite material is supported. Tofacilitate removal from a supporting tool or mold of an axisymmetriccomposite component having features formed therein, the tooling assembly500 includes the segmented tool 504 that is received within the maintool 502. More particularly, the segmented tool 504 fits within the maintool 502 in the one or more areas in which features are to be formed inthe composite component. For example, the segmented tool 504 surroundsan area of the composite material where a countersink 106, counterbore108, or other feature and/or aperture 128 are to be formed, as shown inFIG. 16A, or where a pin 414 is to be embedded in the compositecomponent, as shown in FIG. 16B. The number of segments in the segmentedtool 504 depends on the number and angular spacing of the apertures 128in the composite material 102, in which a feature forming tool or a pin414 are received, as well as the draft angle of any countersink orcounterbore features 106, 108.

When the segments of the segmented tool 504 are positioned within themain tool 502, the main tool 502 and the segmented tool 504 define atooling surface 506. Further, one or more seals 508, such as O-rings orthe like, may be positioned between the segments of the segmented tool504 and the main tool 502. Moreover, a composite material 102 may bedeposited on the tooling surface 106, e.g., a plurality of compositeplies 102 may be laid up on the tooling surface 506 or the compositematerial 102 may be otherwise deposited on the tooling surface 506, suchas through spraying or the like. The first segment 504 a of segmentedtool 504 defines a tooling aperture 509, into which an aperture formingtool may be inserted to form the aperture 128 in the composite material102. The aperture forming tool may be similar to the tool 132 describedwith respect to FIGS. 5B and 6 or the tool 332 described with respect toFIGS. 11B, 11C, and 11D; the aperture forming tool may have otherconfigurations as well.

A feature forming tool 510 may be brought into contact with theplurality of composite plies 102 supported on the tooling assembly 500.Referring to FIG. 16A, the feature forming tool 510 may be configuredsubstantially similar to the feature forming tool 310 described withrespect to FIGS. 10A through 11F or the feature forming tool 410described with respect to FIG. 14. More particularly, as shown in FIG.16A, the feature forming tool 510 comprises a stem 512 and a featureforming head 514. The stem 512 extends through the aperture 128 formedin the composite plies 102 and into the tooling aperture 509 defined inthe first segment 504 a of segmented tool 504. The feature forming head514 guides and presses the composite plies 102 into a recess 516 definedin the first segment 504 a. One or more seals 518, such as O-ring sealsor the like, may be positioned between the feature forming tool stem 512and the first segment 504 a, e.g., to provide a seal between the stem512 and the segmented tool 504 if required. Further, like featureforming head 314 of feature forming tool 310, the feature forming head514 of FIG. 16A may comprise a cap and/or edge formed from a firstmaterial, such as silicone, while the remainder of the head 514 isformed from a second material having a greater Shore hardness than thefirst material. In other embodiments, the feature forming head 514 maybe formed entirely from the first material or the second, hardermaterial. However, the first, softer material may be preferable, atleast around the edge of the feature forming head where the compositeplies 102 transition into the recess 516, e.g., to prevent crimping,wrinkling, or the like of the plies 102 around the feature forming tool510 and/or to help keep the plies 102 smooth where a bag is sealed overthe plies 102 as described in greater detail below.

In the embodiment depicted in FIG. 16B, the feature forming tool 510 ispositioned over a pin 414 similar to the embodiment described withrespect to FIG. 13. More specifically, a pin 414 may be inserted intothe aperture 128 and maintained in contact with the composite plies 102,i.e., the feature forming tool 510 prevents the pin 414 from fallingback through the aperture 128. As described with respect to FIG. 13, insome embodiments, the pin 414 is configured to be embedded in thecomposite component 90, e.g., the pin 414 may be formed from a materialthat integrates with the composite material as the composite material istransformed into the composite component 90. For instance, where thecomposite plies 102 are CMC plies 102, the pin 414 may be formed from aceramic material such that the ceramic pin 414 is embedded in thecomposite component 90. Where the composite material 102 is a PMCmaterial 102, the pin 414 may be formed from a metallic material, suchas a metal or metal alloy. In other embodiments, the pin 414 isconfigured to be removed after processing of the composite material,such that the pin 414 is not embedded in the composite component 90 butis used to form a void feature, such as an aperture 128, in thecomponent 90.

Continuing with FIG. 16B, the feature forming tool 510 comprises a disksubstantially similar in shape to the feature forming head 514 of thetool 510 illustrated in FIG. 16A. Bringing the feature forming tool 510of FIG. 16B into contact with the plurality of composite plies 102comprises placing the disk 510 over the pin 414 and against theplurality of composite plies 102. The disk 510 guides and presses theplies 102 into the recess 516 of the first segment 504 a as the disk 510is seated into the recess. Further, similar to the feature forming head314 of feature forming tool 310 and the feature forming head 514 of FIG.16A, the disk 510 may comprise a cap and/or edge formed from a firstmaterial, such as silicone, while the remainder of the disk 510 isformed from a second material having a greater Shore hardness than thefirst material. In other embodiments, the disk 510 may be formedentirely from the first material or the second, harder material.However, the first, softer material may be preferable, at least aroundthe edge of the feature forming head where the composite plies 102transition into the recess 516, e.g., to prevent crimping, wrinkling, orthe like of the plies 102 around the feature forming tool 510 and/or tohelp keep the plies 102 smooth where a bag is sealed over the plies 102as described herein.

FIG. 17 provides a flow diagram illustrating a method for formingfeatures in composite components according to another exemplaryembodiment of the present subject matter. The exemplary method 1700 maybe used to form a composite component having one or more formed infeatures, i.e., features defined in the component without machining thefeatures in the component after processing the composite material 102.As described with respect to FIGS. 16A and 16B, in some embodiments, atooling assembly 500 comprising a main tool 502 and a segmented tool 504may be used to support a composite material to be formed into acomposite component having one or more features defined therein. Asshown at 1702 in FIG. 17, in an exemplary method 1700 utilizing thetooling assembly 500, the two or more segments of the segmented tool 504must first be installed within the main tool 502. The two or moresegments of the segmented tool 504 define one or more recesses 516 forforming features in the composite component; for example, as illustratedin FIGS. 16A and 16B, a first segment 504 a defines a recess 516 forforming a counterbore feature 108 in the composite component 90.

After the tooling assembly 500 is assembled, a composite material 102 isdeposited on the tooling assembly 500 having recesses 516, as shown at1704 in FIG. 17. In some embodiments, the composite material 102 is inthe form of a plurality of composite plies 102, which, as generallydescribed above, may be formed from composite tapes having a compositematrix material embedded within a reinforcement material and may be laidup on the tooling assembly 500. In other embodiments, the compositematerial 102 is in a form other than composite plies and, for example,may be sprayed or otherwise deposited on the tooling assembly 500.

After the composite material 102 is deposited on the tooling assembly500, as illustrated at 1706 in FIG. 17, one or more apertures 128 may beformed in the composite material 102. In one embodiment of method 1700,the apertures 128 may be formed with an aperture forming tool 132described with respect to FIGS. 5A, 5B, and 6. For instance, theaperture forming tool 132 may be aligned with a tooling aperture 509 inthe segmented tool 504 and driven through the composite material 102supported on the tooling assembly 500 and into the tooling aperture 509.The aperture forming tool 132 may have a sharp end 134 a that forms anaperture 128 in the composite material 102 as the tool is driven throughthe material. Finally, the tool 132 is removed from the compositematerial 102, leaving the aperture 128 in the material 102. Inalternative embodiments, the aperture 128 may be formed using anaperture forming tool 332 described with respect to FIGS. 11A through11F. Other aperture forming tools and ways of forming the one or moreapertures 128 may be used as well. For example, particularly where thecomposite material 102 is a plurality of composite plies, theaperture(s) 128 may be cut in each ply 102 before laying up the plies onthe tooling assembly 500, such that the aperture(s) 128 in each ply 102are aligned as the plies 102 are laid up on the tooling assembly 500.Further, as previously described, the centerline CL_(A) of each aperture128 may be the same as the centerline CL_(F) of the respective feature106, 108, etc. such that the aperture(s) 128 may help align a featureforming tool with the recess(es) 516.

Next, as shown at 1708 in FIG. 17, a feature forming tool 510 isdeployed to press the composite material 102 into the recess(es) 516 toform features of the composite component. In one embodiment, asdescribed with respect to FIG. 16A, a stem 512 of the feature formingtool 510 is inserted into the aperture 128 formed in the compositematerial 102 such that the stem 512 is inserted through the material 102and into the tooling aperture 509 of the first segment 504 a. The stem512 thereby aligns the feature forming head 514 of the tool 510 with therecess 516. As such, as the stem 512 is advanced into the toolingaperture 509 and the feature forming head 514 is brought into contactwith the plurality of composite material 102, the feature forming head514 guides and presses the composite material 102 into the recess 516.The stem 512 may be advanced into the tooling aperture 509 until an edgeof the feature forming head 514 contacts an outermost surface 102 a ofthe composite material 102 supported on the tooling assembly 500.

In other embodiments of method 1700, deploying the feature forming tool510 as shown at 1708 in FIG. 17 comprises inserting a pin 414 throughthe composite material 102 and into the tooling aperture 509 and placinga generally disk-shaped tool 510 over the pin 414, as described withrespect to FIG. 16B. More particularly, after the pin 414 is insertedinto the aperture 128, the disk-shaped feature forming tool 510 ispositioned over the pin 414, and the disk 510 guides and presses thecomposite material 102 into the recess 516 of the segmented tool 504 asthe disk 510 is seated into the recess. The disk-shaped feature formingtool 510 may be seated within the recess 516 when an edge of the disk510 is in contact with the outermost surface 102 a of the compositematerial 102 supported on the tooling assembly 500.

After the feature forming tool 510 is deployed to press the compositematerial 102 into the one or more recesses 516, as shown at 1710 in FIG.17, the method 1700 may include sealing a bag 125 around the compositematerial 102 with the feature forming tool 510 in contact with thematerial, as illustrated in FIGS. 16A and 16B. That is, the compositematerial 102 may be bagged for processing with the feature forming tool510 in contact with the material 102. For example, bagging the compositematerial 102 includes enclosing or encasing the material 102 and featureforming tool 510 within a vacuum bag, such as a flexible bladder or thelike formed from any suitable material. A vacuum may be drawn within thevacuum bag through a vacuum port connected to a vacuum pump, e.g., toremove air and volatiles from the composite material 102. In someembodiments, the bag may be omitted, such that method 1700 does notinclude sealing the bag 125 around the composite material 102 on thetooling assembly 500 with the feature forming tool 510 in contact withthe composite material.

Then, as depicted at 1712 in FIG. 17, the composite material 102 isprocessed, e.g., compacted and autoclaved or, more generally, debulkedand/or processed to reduce porosity, with the feature forming tool 510pressing the composite material 102 into the one or more recesses 516 ofthe segmented tool 504. The processed composite material forms a greenstate composite component having the features formed by the interactionbetween the feature forming tool 510 and the recess(es) 516 of thesegmented tool 504. In embodiments of method 1700 that include insertinga pin 414 as part of deploying the feature forming tool 510, the pin 414is fixed or embedded in the green state composite component such thatthe green state composite component includes the pin 414.

As shown at 1714 and 1716 in FIG. 17, after processing, the bag 125 (ifused) and the feature forming tool 510 are removed from the green statecomposite component, and then the green state composite componentundergoes finish processing to produce the composite component 90 havingone or more features, such as a countersink feature 106 and/or acounterbore feature 108. As described above with respect to method 700illustrated in FIG. 7, finish processing of the green state compositecomponent may include one or more processes that may differ depending onthe type of composite material 102 used in the method 1700. In oneembodiment, where the composite material 102 is a CMC material, finishprocessing at 1716 in FIG. 17 includes firing (or burn-off) of the greenstate composite component to produce a fired composite component,followed by densification of the fired composite component to producethe composite component. The firing and densification processes may besimilar to those described above with respect to method 700. Further, asshown at 1718 in FIG. 17, after finish processing the compositecomponent optionally may be finish machined, if and as needed, and/orcoated with one or more coatings, such as an environmental barriercoating (EBC) or a thermal barrier coating (TBC).

Turning now to FIGS. 18 and 19, other assemblies and methods for formingfeatures in composite components will be described in greater detail.The foregoing embodiments generally describe a first tool defining oneor more recesses on which a composite material is deposited, and asecond tool that is brought into contact with the composite material(directly or indirectly, such as through a vacuum bag) to press thecomposite material into the one or more recesses defined by the firsttool. The second tool generally has one or more inserts or a head shapedcomplementary to the one or more recesses of the first tool such thatthe interaction between the inserts or head, the composite material, andthe one or more recesses urges the composite material to conform to theshape of the one or more recesses. However, it will be appreciated that,in other embodiments, an inverse or opposite configuration of the toolscould be used. That is, the second tool, which is brought into contactwith a composite material deposited on the first tool, may define theone or more recesses while the first tool defines one or more raisedfeatures complementary to the shape of the one or more recesses of thesecond tool. As such, the interaction between the raised features, thecomposite material, and the one or more recesses urges the compositematerial to conform to the shape of the one or more recesses.Accordingly, each of the foregoing embodiments, as well as theembodiments of FIGS. 18 and 19, illustrate a first tool and a secondtool, the first tool having one or more elements, such as recesses orraised features, that interact with one or more elements of the secondtool, such as recesses, inserts, or forming heads, to form one or morefeatures of a composite component.

FIG. 18 illustrates one example of such an inverse or oppositeconfiguration. Similar to the embodiment depicted in FIGS. 8A and 8B,the exemplary embodiment of FIG. 18 illustrates a base tool 200comprising a proximal surface 200 a opposite a distal surface 200 b, aswell as one or more raised features 203 extending from the proximalsurface 200 a. A plurality of composite plies 102 may be laid up on theproximal surface 200 a of the base tool 200. A feature forming tool 210,comprising a shank 216 and a feature forming head 218, may be broughtinto contact with the plurality of composite plies 102 to help defineone or more features of a composite component 90 formed from the plies102, such as a countersink feature 106 (FIG. 2), a counterbore feature108 (FIG. 2), a locating feature, or additional and/or differentfeatures. More particularly, the feature forming head 218 of the tool210 defines a recess 204 shaped complementary to the one or morefeatures 203 of the base tool 200. As shown in FIG. 18, the featureforming head 218 may be brought into contact with the composite plies102 on base tool 200 to press the plies 102 into the recess 204 suchthat, together, the recess 204 and the raised feature 203 help definethe one or more features of the composite component 90. It will beappreciated that the base tool 200 and feature forming tool 210 may haveother features as described in greater detail with respect to FIGS. 8Aand 8B; for example, the feature forming tool 210 may comprise aplurality of forming members 214 supported by a frame 212, and the basetool 200 may define one or more alignment features 201 for aligning thefeature forming tool 210 with the base tool 200. Further, a method suchas or substantially similar to the exemplary method 900 described withrespect to FIG. 9 may be used to form a composite component having oneor more formed in features, i.e., features defined in the componentwithout machining the features in the component after processing thecomposite material 102, using the base tool 200 and feature forming tool210 illustrated in FIG. 18. However, other suitable methods or processesalso may be used.

FIG. 19 depicts another example of an inverse or opposite configuration,illustrating an embodiment that generally is the inverse or opposite ofthe embodiment illustrated in FIGS. 10A through 11F. More particularly,FIG. 19 illustrates a base tool 300 comprising a proximal surface 300 aopposite a distal surface 300 b, as well as one or more raised features303 extending from the proximal surface 300 a. A plurality of compositeplies 102 may be laid up on the proximal surface 300 a of the base tool300. A feature forming tool 310, comprising a stem 312 and a featureforming head 314, may be brought into contact with the plurality ofcomposite plies 102 to help define one or more features of a compositecomponent 90 formed from the plies 102, such as a countersink feature106 (FIG. 2), a counterbore feature 108 (FIG. 2), a locating feature, oradditional and/or different features. More particularly, the featureforming head 314 of the tool 310 defines a recess 304 shapedcomplementary to the one or more features 303 of the base tool 300. Asshown in FIG. 19, the feature forming head 314 may be brought intocontact with the composite plies 102 on base tool 300 to press the plies102 into the recess 304 such that, together, the recess 304 and theraised feature 303 help define the one or more features of the compositecomponent 90. It will be appreciated that the base tool 300 and featureforming tool 310 may have other features as described in greater detailwith respect to FIGS. 10A through 11F; for example, a tip end 312 b ofthe stem 312 of the feature forming tool 310 may be inserted through thecomposite plies 102 to form an aperture therein, or the tip end 312 bmay be drawn through an aperture formed in the plies 102 and into anaperture in the base tool to bring the feature forming tool 310 intocontact with the plies 102. Further, a method such as or substantiallysimilar to the exemplary method 1200 described with respect to FIG. 12may be used to form a composite component having one or more formed infeatures, i.e., features defined in the component without machining thefeatures in the component after processing the composite material 102,using the base tool 300 and feature forming tool 310 illustrated in FIG.19. Other suitable methods or processes may be used as well.

In addition, although described only with respect to base tool 200 andfeature forming tool 210, as well as base tool 300 and feature formingtool 310, it will be understood that, where appropriate, a generallyinverse or opposite configuration of any of the embodiments describedherein may be utilized to form a composite component having one or moreformed in features. Moreover, it will be appreciated that the assembliesand structures for forming one or more features of a composite componentdescribed herein also are by way of example only. Additionally, theforegoing methods 700, 900, 1200, 1500, and 1700 for forming one or morefeatures of a composite component, e.g., a CMC or PMC component such asa gas turbine engine exhaust liner, are provided by way of example only.For example, other known methods or techniques for depositing compositematerial on a tool or tooling assembly, compacting and/or curing thecomposite material, and/or finish processing a green state component,may be utilized. Alternatively, any combinations of these or other knownmethods or techniques may be used to form a composite component havingone or more features defined therein.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal language of the claims.

What is claimed is:
 1. A method for forming features in a compositecomponent, comprising: depositing a composite material on a base tool;aligning an aperture forming tool with a tooling aperture in the basetool; inserting the aperture forming tool through the composite materialto form an aperture in the composite material; removing the apertureforming tool from the composite material; deploying a feature formingtool to press the composite material into one or more recesses, thefeature forming tool comprising a feature forming head; and processingthe composite material with the feature forming tool in contact with thecomposite material, the processed composite material forming a greenstate composite component, wherein the feature forming head isconfigured to form a feature of the composite component.
 2. The methodof claim 1, further comprising, after inserting the aperture formingtool and prior to removing the aperture forming tool from the compositematerial: removing a sharp end from the aperture forming tool, a shaftof the aperture forming tool remaining in contact with the compositematerial; and attaching the feature forming tool to the shaft of theaperture forming tool.
 3. The method of claim 1, wherein the base tooldefines the one or more recesses and comprises a proximate surface thatcontacts the composite material laid up on the base tool, wherein thebase tool further comprises a distal surface opposite the proximatesurface, wherein the tooling aperture extends from a distal end at thedistal surface to a proximate end at one of the one or recesses, andwherein the aperture forming tool is inserted into the tooling aperturethrough the distal end.
 4. A method for forming features in a compositecomponent, comprising: depositing a composite material on a base tool;forming an aperture through the composite material; bringing a featureforming head of a feature forming tool into contact with the compositematerial; and processing the composite material with the feature forminghead in contact with the composite material, the processed compositematerial forming a green state composite component, wherein the featureforming tool comprises a stem extending through the composite materialand into the base tool, wherein the feature forming head comprises anedge formed from a first material, wherein the remainder of the featureforming tool is formed from a second material, the second material beingharder than the first material, and wherein the feature forming head isconfigured to form a feature of the composite component.
 5. The methodof claim 4, further comprising, after bringing the feature forming headinto contact with the composite material and before processing thecomposite material: sealing a bag around the feature forming tool andthe composite material.
 6. The method of claim 4, further comprising,after processing the composite material with the feature forming head incontact with the composite material: removing the feature forming toolfrom the green state composite component; and finish processing thegreen state composite component to produce the composite component. 7.The method of claim 4, further comprising, prior to bringing the featureforming head into contact with the composite material: inserting thefeature forming tool through the aperture.
 8. The method of claim 4,wherein forming the aperture through the composite material comprisesusing a guide tool to push a stem attached to a stop away from thecomposite material, the stop positioned against an outermost surface ofthe composite material, and to push a sharp end of an aperture formingtool through a tooling aperture in the base tool and into the stop. 9.The method of claim 4, further comprising, prior to depositing thecomposite material on the base tool: assembling a tooling assembly withthe base tool, wherein a portion of the tooling assembly is positionedin a passage defined in the base tool.
 10. The method of claim 4,wherein a seal is positioned between the stem of the feature formingtool and the base tool.
 11. The method of claim 4, wherein forming theaperture through the composite material comprises piercing the compositematerial with an aperture forming tool, and wherein bringing the featureforming tool into contact with the composite material comprisesattaching the feature forming tool to the aperture forming tool anddrawing the aperture forming tool back through the composite materialuntil the feature forming head of the feature forming tool is in contactwith an outermost surface of the composite material.
 12. A method forforming features in a composite component, comprising: depositing acomposite material on a tooling assembly, the tooling assemblycomprising a shoulder bushing, the shoulder bushing positioned in a basetool and defining an opening therethrough, the shoulder bushing have afirst end opposite a second end, the first end adjacent the compositematerial deposited on the tooling assembly, the second end extendingthrough the base tool; securing an end cap on the second end of theshoulder bushing; forming an aperture through the composite material;inserting a pin into the aperture such that the pin extends through thecomposite material and into the tooling assembly, the pin inserted intothe opening in the shoulder bushing; and processing the compositematerial with the pin extending through the composite material, theprocessed composite material forming a green state composite component,wherein the pin is fixed in the green state composite component suchthat the green state composite component includes the pin.
 13. Themethod of claim 12, further comprising, after inserting the pin andbefore processing the composite material: sealing a bag around thecomposite material and the pin.
 14. The method of claim 12, wherein thetooling assembly comprises a main tool and a segmented tool, thesegmented tool comprising two or more segments that fit within the maintool, the segmented tool defining one or more recesses for formingfeatures in composite components.
 15. The method of claim 12, furthercomprising, after inserting the pin but before processing the compositematerial, placing a feature forming tool over the pin and against anoutermost surface of the composite material, wherein the feature formingtool is a thin disk.
 16. The method of claim 12, wherein the compositematerial is a ceramic matrix composite material, and wherein the pin isa ceramic pin.
 17. The method of claim 12, wherein the compositematerial is a polymer matrix composite material, and wherein the pin isa metal pin.